MORGAN HEBARD 



Method 



The armament of the ventro-cephalic margins of the cephalic 

 femora has been classed as type i or A, showing a gradual reduc- 

 tion in size and length of spines distad, and type 2 or B, showing 

 spines which change abruptly from elongate and heavy proximad, 

 to very much shorter and more delicate distad. This distinction 

 is found to be too general, and is only mentioned here when roughly 

 indicating the general character of the armament of these margins 

 as found in certain genera. Generic and even specific differences 

 of degree are found, which can not be characterized properly with- 

 out detailed description. It would be convenient if, in describing 

 different genera, such terms as "strongly type A" or "type B 

 approaching type A" could be used, but it is clear that for each 

 author, such comparative words would be apt to have a somewhat 

 different significance. 



The male sex in many species has been found to have very im- 

 portant diagnostic features in the chitinous processes concealed 

 between the supra-anal and subgenital plates. As these parts 

 have never been used to any extent in systematic studies, we have 

 been obliged to supply the following terms. The orifice in which 

 these processes are found is termed the "anal chamber." The proc- 

 esses themselves are termed the "concealed genitalia," of which the 

 longest and most highly specialized is termed the "genital hook." 

 The function of the various processes as yet remains undetermined. 



The exposed portions of the supra-anal and subgenital plates are 

 alone considered in the descriptions of these structures. In the 

 majority of species, the male anal chamber extends to the base of 

 the second ventral (penultimate) abdominal segment preceding 

 the subgenital plate. The subgenital plate is found to extend to 

 this point, though subchitinous in structure in the concealed por- 

 tion. 



Measurements. The body length is found useful, but it must 

 be understood that it would vary in the same specimen in life, due 

 to the contraction or extension of the abdomen; in consequence, 

 when abdominal distortion is evident, the normal length is esti- 

 mated. The body length is considered as the distance from the 



MEM. AM. ENT. SOC. 



